Fix inconsistent host lobby join URL (#1634)

## Description:
Fixes inconsistent host lobby join URL by adding a / before the #

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [ ] I have read and accepted the CLA agreement (only required once).

## Please put your Discord username so you can be contacted if a bug or
regression is found:

DISCORD_USERNAME
Nikola123

src/client/HostLobbyModal.ts

@@ -611,7 +611,7 @@ export class HostLobbyModal extends LitElement {
     try {
       //TODO: Convert id to url and copy
       await navigator.clipboard.writeText(
-        `${location.origin}#join=${this.lobbyId}`,
+        `${location.origin}/#join=${this.lobbyId}`,
       );
       this.copySuccess = true;
       setTimeout(() => {